A standard microscope includes a light source, an objective lens and viewing arrangements (e.g. eyepiece or camera/CRT) for examination or manipulation of objects at high magnifications. Standard microscopes include commercially available petrographic, metallographic and semiconductor microscopes.
Microscopes are designed to include a stage where the specimen (usually mounted onto a glass slide) is placed for observation. A stage can be classified according to design and functionality. In the simplest case, the plain stage assembly consists of a rectangular or square design containing several clips to hold the specimen slide. The stage assembly also contains an opening in the center to allow light from the condenser to pass through the specimen (the stage opening).
The stage assembly is often equipped with a mechanical device that holds the specimen slide in place and can smoothly translate the slide back and forth as well as from side to side. This specimen slide translational control device is commonly referred to as a mechanical stage. This mechanical stage is used to position the specimen or sample within the optical path. Moving the stage forwards and backwards and left and right can thus manipulate the sample. A common convention for naming the left-right and front-back axes is X and Y, respectively.
A simple (commonly termed “plain”) microscope stage assembly contains an opening to admit light from the condenser, occasional mounting holes for mechanical slide holders, and two clips that secure the specimen slide in place for observation under increasing magnification (changing of objectives) and for photomicrography. This plain stage is very useful for quick examination of specimens, but is very difficult to use with higher power objectives (above 20×). At high magnification, small translations of the specimen slide will quickly translate features of interest completely out of the viewing field, leading to frustration during microscopist attempts to relocate them. Auxiliary mechanical stages attached to a simple stage can allow for minute translation of the specimen slide, making it easier for the microscopist to find specific areas on the slide. Furthermore, the auxiliary mechanical stage contains controls so the microscopist can examine the entire microscope slide (secured to the stage with the slide holder).
Although many stage assemblies are known in the art, an exemplar assembly which allows such refined specimen positioning, includes a lower stage fixed indirectly to the microscope stand, an upper stage directly driven and guided with respect to the lower stage by a mechanism such as a ball guide, roller guide, or shaft guide, and a slide mount. The slide mount is inserted between the upper and lower stage by a slide mount guide and allows a specimen to move in a direction perpendicular to the upper stage. Thus, with a slide mount fixed on the slide mount guide, a sample can be maneuvered in two directions.
However, due to the variety of microscopists using these instruments, both left and right-handed stages are required. The location of the stage control mechanism is on the side of the stage matching the user's predominant hand of use. Having to match the stage configuration to the microscopist's predominate hand creates difficulty during manufacture of products. Each microscope must be either a left-handed or a right-handed microscope. After the assembly is complete, changing the configuration requires significant disassembly and reassembly time, as well as requiring a complete additional stage mechanism. This problem also requires microscope manufacturers to maintain inventories of both left-handed and right-handed stage assemblies.
While conventional microscope design has not necessarily been a problem for short-term use, long-term sessions have historically created problems for microscopists. Prolonged use of a microscope may lead to physical (sometimes permanently debilitating) problems especially with the visual and musculoskeletal systems. Thus, as microscopes continue to become more commonplace in geological, biological, and medical laboratories and in factories manufacturing electronic components and integrated circuits for computers and the consumer electronics industry, ergonomic design has become an important consideration.
Ergonomics has been defined as an applied science concerned with designing and arranging things people use so that the people and things interact most efficiently and safely (called also human engineering). Accessibility issues have also required flexibility in microscope design so that those with mobility problems may be able to effectively perform job functions.
What is needed then is a microscope stage apparatus with a bidirectional, ergonomic movement means such that the specimen may be properly oriented upon the stage prior to being inserted into the microscope optical path.